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Expanded metal is awkward to plasma-cut because the torch repeatedly crosses open spaces and thin strands. A standard drag cut can sputter or stop when the arc loses the work. A pilot-arc cutter helps: it starts an arc inside the torch and can keep it lit briefly while crossing gaps. That does not make every machine suitable, though. Amperage, duty cycle, air supply and torch control still determine how cleanly it cuts.
What to look for in a pilot-arc cutter
For common expanded-metal sheets, a 30–40 amp machine is a practical starting point. It has enough output for thin steel and light fabrication, while remaining easier to power than many larger units. Choose 45–60 amps if you also expect to cut thicker plate or run longer cuts. Published maximum cut thickness is usually a best-case figure; for clean, repeatable cuts, look for a rated or recommended cut capacity instead.
Check the duty cycle at the amperage you will actually use. A rating of 60% at 40 amps means about six minutes of cutting in a ten-minute period under the stated test conditions, followed by cooling time. Thin expanded metal usually requires little arc-on time, but long perimeter cuts and production work can expose a low duty cycle.
Air quality matters as much as the cutter. Follow the manufacturer’s pressure and flow requirements, use a compressor that can sustain them, and install a suitable filter or water separator. Wet or oily air wears consumables quickly and can cause erratic arcs. A small compressor may show adequate pressure while idle, then sag as soon as the torch is triggered.
Pilot-arc cutter types compared
| Type | Best fit | Trade-off |
|---|---|---|
| 30–40 amp, 120/240V dual-voltage | Home shops, thin sheet and occasional expanded-metal work | Portable and versatile, but limited for thick plate or sustained cutting |
| 45–60 amp, 240V | Regular fabrication and mixed sheet-and-plate work | More cutting headroom; needs a suitable 240V circuit and stronger air supply |
| Low-cost compact pilot-arc unit | Infrequent repairs and light-duty projects | May have lower duty cycle, less consistent consumables availability or less clear specifications |
For occasional work on thin expanded metal, a capable 30–40 amp dual-voltage machine is often enough. Spend more for a larger unit if you regularly cut thicker stock, need faster travel, or will be cutting for long stretches. A larger amp rating alone does not guarantee a better result; verify that the torch, air requirements and duty cycle suit your work.
Buying options by use
For a general-purpose shop, compare 40 amp dual-voltage pilot-arc plasma cutters. Check the manual for input-current requirements on both voltages, rated cut thickness and compatible torch consumables. Running on 120V can be convenient, but it generally limits available output; use 240V when the job calls for it and your circuit supports it.
If you routinely cut thicker material or work through batches, look at 50 amp, 240V pilot-arc cutters. Confirm the breaker and receptacle requirements before ordering. A machine that demands a circuit you do not have can turn a good purchase into an electrical project.
For occasional repairs on thin stock, a compact pilot-arc cutter may be the economical choice. Do not buy on advertised maximum thickness alone. Look for a real manual, available replacement electrodes and nozzles, and a clear explanation of air pressure and duty cycle.
How to cut expanded metal cleanly
Support the sheet so it cannot vibrate or sag, but leave enough clearance below the cut for sparks and slag to escape. Expanded metal has sharp edges and can shift under the torch, so clamp it securely at several points. Wear eye and hearing protection, gloves and flame-resistant clothing; plasma cutting throws hot particles, and the openings in the sheet do not make it safe to handle casually.
Use the torch’s recommended standoff or drag tip, depending on the consumables supplied. Keep a steady, moderate travel speed and hold the torch close to square with the sheet. Moving too slowly can widen the kerf, melt adjacent strands and leave heavy dross. Moving too quickly can produce an incomplete cut, especially when crossing a thicker rib. Make a short test cut on offcut material before starting the finished piece.
A pilot arc reduces nuisance interruptions over the openings, but it does not eliminate them. If the torch repeatedly goes out, check for a loose work clamp, poor contact through paint or rust, a kinked air hose, insufficient compressor output or worn consumables. Attach the ground clamp to clean metal on the workpiece or a secure conductive table. Replace a damaged nozzle or electrode rather than compensating by slowing down excessively.
Before you buy
Compare total setup cost, not just the cutter price: you may need a compressor, air treatment, a suitable outlet, a torch consumable kit and a safe cutting surface. Confirm that replacement parts are readily available and that the manufacturer specifies the air flow as well as pressure. For occasional thin expanded-metal cuts, a modest machine with reliable consumables is usually a better buy than an oversized cutter with no practical power supply. For frequent work, prioritize a stable 240V setup, a useful duty cycle and a torch that remains comfortable to guide across a full sheet.